Default Folder Help

I have an active picture that, when user click on it with left mouse button, is supposed to open file selector. But I have a global value I'd like to use which changes the default folder to load images from. In other words, I don't want the file selector to leave the application's root path. But I want this global value to point to different folders. Example:

pseudo code:

If global value A = 1
Have active picture load image from selector in folder A.
If global value A = 2
Have active picture load image from selector in folder B.

etc.

Can someone tell me what object(s) I'll need? I tried File object and it didn't work, I also tried Common Dialogue but it didn't work.

File object works fine. What do you mean by "it didn't work"? That could mean anything from "it didn't let me select it in the new object list" to "it didn't open the file selector even when I used the correct actions"

Here is a simple example: http://mfa.aquadasoft.com/view/1293126761-DifferentPaths
All I did was make it start browsing from a different folder based on which radio button you chose. The rest, such as getting the selected file, is pretty simple.